First Aid for the USMLE Step 2 CS

Section 4. Practice Cases

Case 25. 18-Month-Old Girl with Fever


Opening Scenario

The mother of Maria Sterling, an 18-month-old female child, comes to the office complaining that her child has a fever.

Examinee Tasks

1. Take a focused history.

2. Explain your clinical impression and workup plan to the mother.

3. Write the patient note after leaving the room.

Checklist/SP Sheet

Patient Description

The patient’s mother offers the history; the child is at home.

Notes for the SP

Show concern regarding your child’s situation.

Challenging Questions to Ask

 “Do you think that I did the right thing by coming here and telling you about my child’s fever?”

 “Is my child going to be okay?”

Sample Examinee Response

“You certainly did the right thing by coming in today. Maria may have an infection that is causing her fever, so we need to examine her here in the office and then decide whether she needs any tests and/or treatment.”

Examinee Checklist

Building the Doctor-Patient Relationship Entrance

 Examinee knocked on the door before entering.

 Examinee introduced self by name.

 Examinee identified his/her role or position.

 Examinee correctly used patient’s name.

 Examinee made eye contact with the SP.

Reflective Listening

 Examinee asked an open-ended question and actively listened to the response.

 Examinee asked the SP to list his/her concerns and listened to the response without interrupting.

 Examinee summarized the SP’s concerns, often using the SP’s own words.

Information Gathering

□ Examinee elicited data efficiently and accurately.

Connecting with the Patient

□ Examinee recognized the SP’s emotions and responded with PEARLS.

Physical Examination



 Examinee discussed initial diagnostic impressions.

 Examinee discussed initial management plans:

□ Follow-up tests.

 Examinee asked if the SP had any other questions or concerns.

Sample Closure

Mrs. Sterling, it appears that your child is suffering from an infection that may be viral or bacterial. She may be suffering from an ear infection or something more serious. A physical exam and some blood tests will be needed to identify the source of infection and the type of virus or bacteria involved. Although viral infections generally clear on their own, most bacterial infections require antibiotics; however, such infections generally respond well to treatment. Do you have any questions for me?


HPI: History obtained from mother. Patient is 18-month-old F with fever x 2 days.

 Temperature recorded at home, 101°F.

 Tired and not playing with toys or watching TV as usual.

 Pulling at right ear.

 Difficulty swallowing and sleeping x 2 days.

 Loss of appetite.

 One episode of vomiting.

 Maculopapular facial rash that spread over the chest, back, and abdomen, sparing the arms and legs.

 Attends day care center, no known history of sick contacts.

 No ear discharge.

 History of cough and runny nose for a few days last week.

ROS: Negative except as above.

Allergies: NKDA.

Medications: Tylenol.

PMH: Otitis media 3 months ago, treated with amoxicillin.

Birth history: 40-week vaginal delivery with no complications.

Dietary history: Formula milk and solid food. She was not breast-fed.

Immunization history: UTD.

Developmental history: Last checkup was 1 month ago and showed normal weight, height, hearing, vision, and developmental milestones.

Physical Examination


Differential Diagnosis


Patient Note Differential Diagnoses

 Acute otitis media: Infections of the middle ear are more common in younger children because of their shorter and more horizontal Eustachian tubes. Fever, otalgia, loss of appetite, temporary hearing loss, and general irritability suggest this diagnosis but are not always present. Upper respiratory viral infection is a common risk factor for developing acute otitis media. This patient has a recent history of cough and runny nose, both of which are suggestive of a viral URI. In addition, patients with a prior history of otitis media are more prone to having another episode.

 Meningococcal meningitis: Fever, lethargy, and a possible petechial rash suggest meningococcemia. Patients may also have headache, vomiting, photophobia, neck stiffness, and seizures. This patient had a single episode of vomiting. Although her immunizations are up to date, meningococcal vaccinations are typically not given until 11-12 years of age; therefore, at 18 months, the patient would not yet have been immunized. Treatment is critical, as meningococcal meningitis is a severe, rapidly progressive, and sometimes fatal infection.

 Scarlet fever: This patient has fever, difficulty swallowing (possible pharyngitis), and a rash that started on her face and spread to her trunk. However, the history does not indicate whether the rash consists of a diffuse erythema with punctate, sandpaper-like elevations that spare the area around the mouth. In addition, scarlet fever is more common among school-age children. However, the patient does attend day care, where she may potentially have been exposed to sick contacts. Left untreated, Streptococcus pyogenes infection can lead to rheumatic heart disease. A throat culture would aid in identifying this illness.

Additional Differential Diagnoses

 Fifth disease or other viral exanthem: In children, viruses commonly present with low-grade fever and rash. In general, viral exanthems are nonspecific in their appearance and are usually maculopapular and diffuse. Parvovirus B19 infection, or fifth disease, usually presents as intense red facial flushing (a “slapped cheek” appearance) that spreads over the trunk and becomes more diffuse. However, almost any virus can be accompanied by rash in a pediatric patient, and it is not always necessary to ascertain which virus is causing the illness. If the illness is prolonged or particularly troublesome, viral cultures, molecular tests (PCR), and/or antibody titers can be ordered to determine the exact etiology.

 Varicella: Fever and rash, along with day care attendance, are consistent with this infection. In varicella, lesions are present in various stages of development at any given time (eg, red macules, vesicles, pustules, crusting), and the rash is intensely pruritic. Because the patient’s immunizations are up to date, it is unlikely that she has varicella.

Diagnostic Workup

 Pneumatic otoscopy: Key to look for the tympanic membrane (TM) erythema and decreased mobility seen in otitis media.

 LP—CSF analysis: Should be performed if there is any concern for meningitis. CSF analysis includes cell count and differential, glucose, protein, Gram stain, culture, latex agglutination for common bacterial antigens, and occasionally PCR for specific viruses.

 CBC with differential, blood culture, UA and urine culture: To isolate Neisseria meningitidis and to screen for occult bacteremia or UTI.

 Throat culture: To isolate S pyogenes, which causes scarlet fever. The rash is pathognomonic for this diagnosis.

 Platelets, PT/PTT, D-dimer, fibrin split products, fibrinogen: Evidence of DIC is often seen in meningococcemia.

 Tympanometry: Useful in infants older than six months of age; confirms abnormal TM mobility in otitis media.

 Parvovirus B19 IgM antibody: The best marker of acute or recent infection in suspected fifth disease.

 Skin lesion scrapings: Varicella antigens are identified by PCR or direct immunofluorescence (DFA) of skin lesions. A Tzanck smear (more of a historic test and no longer recommended) may show multinucleated giant cells in varicella infection.

 Varicella antibody titer: May be useful in uncertain cases (look for a fourfold rise in antibody titer following acute infection).

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